DE69719746T2 - PVC PARTICLE - Google Patents

Abstract

A procedure for the production of PVC particles with a narrow size distribution in the range 10-50 mum, preferably 10-30 mum, in which, in a first stage, a vinyl monomer or a mixture of monomers is polymerised to form a polymer/oligomer seed particle in the range 1-10 mum. In a second stage, another vinyl monomer or mixture of monomers is swelled into the polymer/oligomer seed particles and polymerisation takes place in such a way that they grow into polymer particles of the desired size. It is preferable to use aromatic vinyl monomers or acrylates as the monomer in the seed particles. The seed particles in the first stage can be produced in a two-stage swelling process or by dispersion polymerisation.

Description

The present invention relates to a process for the production of PVC particles, the use of these particles, a PVC mixture and spherical Particle.

After polyethylene is polyvinyl chloride (PVC) the most widely used plastic raw material in the world. In Western Europe alone are yearly more than 5 million tons used. The area of application is very wide, it ranges from hard products such as pipes, profiles and calender film to plasticized products such as electrical Cables, hoses and foils. Both compact and foamed items are common. S-PVC, which is the predominant product variant, is formed by suspension polymerization, around particles in the order of magnitude from 100 to 200 μm to build.

Paste PVC is another type of product which roughly 10% of the total PVC consumption accounts. It is manufactured using different variants of the Emulsion polymerization, and the latices produced are dried, around fine-grained To form polymer particles. The primary particles in the latex can be dependent of the method used is normally from 0.1 to 2 μm. Very special procedures can Particles down to 5 μm produce. The most common The drying process is spray drying, which are also a number of secondary particles with different Generated sizes. This powder is in a solvent, dispersed the plasticizer to a liquid plastisol or to form a paste. The processing takes place in procedures such as coating (reverse roll coating, knife coating processes, Screen coating), gravure and screen printing, rotary casting, lintel casting and Immerse in liquid Form instead. The main product areas are floors, wallpaper, Tarpaulins, rainwear, covers and gloves.

Filler PVC (Foreign resin) is a special product, which with standard paste PVC is mixed in plastisol formulations to meet both high and even at lower shear rates during the manufacturing process the best possible To generate flow. The admixture of filler PVC is used for the flow of the resulting plastisol can also be beneficial in cases where there is a need consists of the plasticizer content in the formulation to decrease or if possible high molecular plasticizers with a low vapor pressure to use. The reason for this is that a mixture of small and large particles creates a denser one Degree of packing and thus a less efficient particle concentration generated. Then there is a larger proportion of the plasticizer free to flow in the plastisol to create. Existing filler PVC products are produced by suspension polymerization. Particle sizes below of 60 μm are through special measures achieved, such as the use of surfactants and modified Stirring conditions.

Products with an average Diameter in the order of magnitude from 35 to 45 μm are the market leaders. But it is very difficult with this procedure to have narrow size distributions to produce, and therefore the products also contain a certain one Proportion of particles with more than 60 μm. This is a major limitation in the Application area because processes such as thin-film coating, roller coating, Roll coating, wallpaper making and media printing processes with very fine particles. With a particle size of 40 up to 50 μm it is impossible, To produce films that are thinner are as 100 μm. Known procedures within this area are carefully described by M. J. Bunten in "Encyclopedia of Polymer Science and Technology; Vinyl Chloride Polymers, Polymerization ", 2nd Edition, Volume 17, 1982, which is hereby used as a reference.

The article by R. D. Sudduth (J. of Applied Polymer Science, 48, 37-55 (1993)) states that, if the ratio between the diameters of large and small particles exceeds 10, the maximum degree of packing has been reached. This means that a Mixture of particles with 20 and 2 μm is just as cheap as a mixture of Particles with 40 and 2 μm, and that equally good flow conditions where plastisol can be expected. That is why it is unnecessary to have large particles to have, which limit the area of application.

The object of the present invention is the production of PVC particles with a narrow size distribution in the order of magnitude from 10 to 50 μm. Another task is to make spherical, almost monodisperse PVC particles in the order of magnitude from 10 to 50 μm manufacture, and such particles in formulations and processes to use to manufacture products based on paste PVC processes based.

These and other tasks of the present Invention are achieved as described in the appended claims. The present Invention is also described below.

The present invention relates to a process for the production of PCV particles with a narrow size distribution in the order of 10 to 50 μm, preferably 10 to 30 μm, in which, in a first step, an aromatic vinyl polymer, acrylates or a mixture of monomers is polymerized in order to to form a polymer / oligomer seed particle in the order of 1 to 10 microns. In a second stage, another vinyl monomer or a mixture of monomers is swelled into the polymer / oligomer seed particles and the polymerization is carried out in such a way that they grow into polymer particles of the desired size. The use of aromatic vinyl monomers or acrylates as monomers in the Seed particles are preferred. The seed particles in the first stage can be produced by means of a two-stage swelling process or by means of dispersion polymerization. If dispersion polymerization is used, it is preferred to initiate the polymerization by metering a preheated mixture of an initiator and a solvent so that the temperature in the medium does not change significantly during the period in which the particles are germinated. It is particularly preferred to separate the particles from the reaction medium and to clean them of additives before transferring them to the second stage of the process.

It is preferred that the through Dispersion polymerization produced seed particles by swelling in a mixture of an oil-soluble Initiator and a monomer are activated before the initiator decomposes and for execution more monomer is added to the polymerization. Oil-soluble organic peroxides or azo initiators are used for use in the first stage as polymerization initiators prefers. The polymerization can also be done using the leftover Initiator can be carried out in the seed particles. It is preferred to carry out the second stage with continuous addition of monomer in order to Avoid phase separation problems.

It is preferred to manufacture the seed particles in the first stage to dispersion polymerization use, using an oil-soluble organic peroxide as a polymerization initiator, and in the second stage only the polymerization medium, Add stabilizing agent, monomer and initiator activator and that using the polymerization in the second stage of the leftover Initiator is carried out in the seed particles. The present invention also includes a PVC mixture containing, in particular for plastisol purposes spherical PVC particles in the order of magnitude from 10 to 50 μm, in particular 10 to 30 μm, with a narrow size distribution, normal paste PVC, 0 to 100 parts plasticizer, 0.1 up to 10 parts of heat stabilizer and 0 to 100 parts of others normal additive for PVC based products. The spherical particles in the order of magnitude from 10 to 50 μm can from 0 to 100% of the total PVC content make up the wording. It is preferred as the normal paste PVC in such mixtures fine-grained Products without large agglomerated secondary particles to use. Such products can be used for Thin film products, such as wallpaper, covers and decorative film or for printer ink in engraving or screen printing processes or for textile coating processes and clothing fixation.

Spherical PVC particles in the order of magnitude from 10 to 50 μm and in particular i 0 to 30 μm with a narrow size distribution, made according to the present Invention, can as a viscosity reducer used in other polymer systems or in liquids, in which other polymers are not present than fillers in pillars for separation purposes or as a base particle for further chemical modification.

The production of the mentioned PVC particles with a narrow size distribution takes place in a two-stage process. First, a vinyl monomer or a mixture of monomers polymerized to polymer / oligomer seed particles to build. In a second stage, another vinyl monomer or a mixture of monomers swelled into the polymer / oligomer seed particles and the polymerization takes place in such a way that they grow into polymer particles of the desired size.

Polymer / oligomer particles from aromatic Vinyl monomers or acrylates are the seed particles in vinyl chloride polymerization advantageous. This is because such particles are relatively light can be produced using known methods to achieve the desired size and size distribution to create. Another advantage is that it works with a specific Oligomer content can be generated, which is dramatic Increase in source capacity for the Vinyl chloride monomer generated in the second stage. Thus, it is possible to end particles guarantee with a very low content of germ particles. But a problem with this two-step germination process is that the mixture of incompatible systems for phase separation to lead can and the production of perfect spherical particles is impossible. On the reason for this is the difference in interfacial tension between the vinyl chloride, Polyvinyl chloride and the germ. If polystyrene as the seed particles is used, the compatibility between this phase and be bad for polyvinyl chloride, and it gets worse with increasing Extent of Swelling a phase separation occur. It is therefore more advantageous To use methyl methacrylate as the monomer for the seed particles since polymethyl methacrylate has a relatively good compatibility with PVC has. PMMA also produces better outdoor stability of the end products than they do is produced with aromatic compounds.

But a special property of polyvinyl chloride is that the polymer is not soluble in its own monomer. Furthermore, there is also a very large difference in density between the monomer and the polymer (0.9 and 1.39 g / cm ³ ). As a result, perfectly spherical particles are not formed for PVC above a certain size (approximately 1 μm) when using traditional manufacturing processes. An object of the present invention was to avoid this problem, so that it is possible to produce spherical particles of 10 to 50 μm.

The seed particles can be produced in various processes. One possibility is the use of the two-stage swelling method described by Ugelstad ("Advances in Colloid and Inter face Science ", vol. 13, 101-149, 1980). Such a seed will have a large swelling capacity and the particle size can be easily controlled. At the same time, this method produces a very narrow particle size distribution because it starts with seed particles with a narrow size distribution But there is a limitation that multi-stage polymerization is required to achieve particles of a certain size.

Another manufacturing process of dispersion particles. This is a relatively new process, which is described in the literature, see for example Shen et al. ("Journal of Polymer Science; Part A: Polymer Chemistry ", volume 31, 1393-1402, 1993) and Paine et al. ("Journal of polymer science; Part A: Polymer Chemistry ", vol. 28, 2485-2500, 1990). This Procedure allows the direct production of particles with diameters of up to 10 μm and a narrow size distribution.

According to the present invention did it become possible separate the particles from the dispersion medium and put them into one to transfer new polymerization medium. So you can used as a seed in conventional polymerization processes become. This is therefore a simple process for the production of seed particles with good swelling properties. Another improvement in Swelling properties can be increased by using a chain transfer agent while of the polymerization are generated so that the molecular weight a cheaper one Level is reduced. In many cases, this can be beneficial. Size Amounts of solvents and additives used in the dispersion polymerization process. A procedure, which contains the reuse of the reaction medium therefore of great Be an advantage. Shen et al. also describe another polymerization, in the polystyrene particles produced by dispersion polymerization can be used as a seed, but in this case the continuous medium not changed.

Reuse of reaction medium is possible using a direct process in which the particles are separated become and the medium for a new reaction is used, preferably in a mixture with a fresh solution. Another method is to filter the particles or centrifuge them out and the solvent using known techniques such as distillation. The consumption of the solution is thus kept to a minimum. Another advantage of one such separation process is that the particles are the same Washed time and thus transferred to the next polymerization stage in a completely clean form without the stabilizers from the dispersion process contaminate the seed polymerization. This is also for the swelling properties the particle cheap, because emulsifiers and dispersants on the surface Prevent diffusion into the particles. Another advantage is that there are no restrictions in the choice of stabilizers in the crucial polymerization there and good control of particle formation is achieved.

To the new formation of particles outside of the swollen germ particles during to avoid polymerization in the second stage, it is a Advantage to have a continuous addition of the monomer. Therefore finds polymerization with vinyl chloride at a pressure below of the saturation pressure of the monomer at a certain temperature. Among such Conditions, the monomer does not appear as a separate phase in the reaction medium and the likelihood of secondary nucleation processes thus greatly reduced. A continuous addition of the monomer can be ensured in the case of vinyl chloride by adding a pump be facing each other the pressure in the reactor is regulated. The pressure becomes constant held and when the monomer is consumed, monomer is added. On another method is to have two reactors operating in one Way connected in series that the VCM pressure in the Reactor with the polymerization reaction by regulating the temperature in the other reactor that is used as the VCM reservoir is regulated. In both of these processes, continuous The monomer is allocated in relation to the reaction rate added. Another advantage of such a continuous addition of the monomer is that the reaction will take place faster than with a standard polymerization, because the work is always Trommsdorf area takes place. So that the properties of the finished Materials as good as possible are, but it is advantageous if possible the pressure as a dose to saturation pressure to keep at the polymerization temperature. A polymerization, which takes place at a pressure which is considerably below the saturation pressure lies, creates a reduced thermal stability in the end product. Another surprising one Result of this procedure for carrying out the polymerization reaction it was that the end particles could easily be made completely spherical. Without a continuous addition of monomer, the shape of the particles was very irregular.

If other monomers with a lot lower vapor pressure than vinyl chloride will be used continuous additions take place using another Principles, such as allocating the monomer as a function of calculated conversion and a calculation of the composition of the polymer in the existing particles in the reaction medium.

It is also crucial to choose a type of polymerization initiator that will produce a desired result. In principle, there is no limit to the type of initiator that can be used. In practice, the oil solubility and reactivity are adapted to the other reaction conditions. It is an advantage to fully or partially oil-soluble peroxides or azo initiators to be used, if possible in combination with so-called redox systems, which enable faster splitting of the initiator and thus a shorter polymerization cycle. The use of a redox system enables good control and monitoring of the speed and consumption of the initiator. It will be possible to swell initiators into the seed particles, if possible using a small amount of solvent or monomer, and they will start the polymerization reaction within the particles after the monomer has been added. Water-soluble initiators can also be used, but the possibility of secondary particle nucleation increases. As is known, this is not desirable. Secondary nucleation in the aqueous phase can be prevented by using radical scavengers such as potassium iodide. Another method is to use the initiator left over in the preparation of the seed particles to initiate the polymerization in stage two.

The production of germ particles according to the dispersion process is described with the use of azo initiators and benzoyl peroxide. A disadvantage of the azo types is that the residues of the initiator in the end product in connection with the manufacture of PVC products act as a foaming agent and therefore special for commercial purposes Precautions must be taken. Residues of Initiators can before the filler PVC particles dry be decomposed, but this requires significant thermal Stress with a resulting reduced thermal stability and irregular distribution of the molecular weight. A solution for this Problem would be the use of a known peroxide initiator for standard PVC production. As described in the examples below, it turned out to be possible out germ particles with an oil-soluble To produce peroxide. In connection with the adaptation of the reaction conditions and the initiator concentrations it also turns out to be possible enough remaining Initiator in the seed particles to get the polymerization to be able to finish in other stages.

To get a successful result for particle production another important element is the choice of stabilizer system, which keeps the particles freely dispersed in the reaction medium. The the present invention has no restrictions on the choice of such Substances. Both standard emulsifiers of anionic or non-ionic Art known from the field of emulsion polymerization, as well Polymer suspending agents of the polyvinyl alcohol types, polyvinyl pyrrolidone, Styrolmaleinsäureanhydridcopolymere and various types of cellulose, such as methylhydroxyethyl cellulose and methylhydroxypropyl cellulose are used. A special one advantageous way which by the use of PVC particles according to the present invention is provided is the use of polymer suspension agents instead of low molecular weight and ionic emulsifiers during the Particle production.

Because of the totally exceptional particle size and the Particle size distribution can the particles according to the present Invention the majority and also the full share of PVC in the Wording for make up the end products. Avoid finished PVC products Disadvantages, such as a higher one Water absorption and the volatile content, which usually accompany standard paste PVC products, which by means of traditional emulsifier for the production of paste PVC has been made.

The present invention will be further illustrated by the following examples and the accompanying ones 1 to 4 illustrates in which:

1 the particles show how they were made in Example B-1.

2 shows the particles made as in Example B-11.

3 shows the particles made as in Example B-13.

4 shows a commercial filler PVC, Vinnol C65 V.

In Examples A-1 through A-7 Thermostat-controlled glass reactor with reflux with 1.1 liters or 5 liters used. In Examples B-1 through B-17, an isothermal Reaction calorimeter (CPA-2, ThermoMetrics, Sweden) with one Reactor with a volume of 200 ml, or thermostatically controlled glass reactor with 1.1 liters or 1.4 liters or a steel reactor with 14 liters used.

Production of germ particles

Test A-1 polystyrene oligomer seed

Monodisperse oligomer particles from PS were prepared by the two-step process described by Ugelstadt ("Advances in Colloid and Interface Science", Vol. 13, 101-149, 1980). An emulsion of dioctanoyl peroxide (20 g), acetone ( 28 g), sodium lauryl sulfate (1.38 g) and distilled water (235 g) were added to a latex made of oligomeric germ (17 g latex = 2.0 g of germ) with a particle size of 1 μm Swollen for 72 hours at 25 ° C. Then styrene monomer (31 g), distilled water (120 g) and potassium iodide (0.2 g) were added and the polymerization was carried out for 165 minutes at 70 ° C. Seed particles became of 2.2 μm. This germ was further swollen with an emulsion of dioctanoyl peroxide (2.03 g), sodium lauryl sulfate (0.34 g) and distilled water (68 g). The swelling took place at 25 ° C for 72 hours and the finished activated seed had a diameter of 3 μm.

Test A-2 polymethyl methacrylate oligomer seed

Oligomer germ produced by PS using the Ugelstad method (1 µm, 2.0 g), was with an emulsion of dioctanoyl peroxide (20 g), sodium lauryl sulfate (1.38 g), acetone (28 g) and distilled water (258 g) for 72 hours swollen at 25 ° C. Then methyl methacrylate (31 g) swollen into the activated seed particles and the polymerization was at 65 ° C for 120 minutes. The finished germ had one Diameter of 3 μm.

Test A-3 polymethylacrylate dispersion seed

Dispersion polymerization of MMA was carried out in methanol with poly (vinyl pyrrolidone) (M _w = 40,000) as the stabilizing agent. The initiator was 2,2'-azobis (isobutyronitrile). As the chain transfer agent for reducing the molecular weight, 2-ethylhexylthioglycolate was used. The recipe for the test is shown in Table 1.

Table 1

PVP and methanol become the boiling point heated and the solution is for 1 hour in an N2 atmosphere cooked. The mixture is cooled to 55 ° C and MMA is added. When a stable temperature of 55 ° C has been reached will be a solution added by AIBN in methanol. The polymerization is carried out at a constant temperature for Carried out for 48 hours. The chain transfer agent can be at any time during the Process are added.

Depending on the exact one used Recipe become particles in the order of magnitude from 0.5 to 10 μm manufactured, and in all cases was the size distribution closely. When the chain transfer agent was used, germ particles became with a larger diameter and a slightly wider size distribution manufactured. The exact size of the dispersion seed PMMA, which has been manufactured and used, is made for everyone Case indicated in the examples of the production of PVC particles.

When the chain transfer agent was used, the procedure was that a solution of PVP K-30 (10.00 g) in methanol (175.75 g) was added to the reactor and the mixture was boiled in an N2 atmosphere for 1 hour , The mixture was cooled to 55 ° C before methyl methacrylate (25.00 g) was added. A mixture of 2-ethylhexylthioglycolate (0.15 g), 2,2'-azobis (isobutyronitrile) (0.30 gl and methanol (39.00 g) was added to the reactor when the temperature was stable at 55 ° C. The polymerization was carried out at 55 ° C for 48 hours.

There were spherical particles with a diameter of 12.5 μm obtained with a small proportion of 4 μm.

Test A-4 polystyrene dispersion seed with dioctanoyl peroxide

A solution made from polyvinylpyrrolidone (PVP K-30) (5.15 g) in ethanol (236.07 g) was heated to the boiling point and for Cooked for 1 hour in an N2 atmosphere. The temperature was regulated to 70 ° C and it became styrene (78.04 g) added. As the temperature stable at 70 ° C was a mixture of dioctanoyl peroxide (4.08 g) and ethanol (35.24 g) was added and the polymerization was continued for 24 hours performed at 70 ° C.

The particles produced had one Diameter of 5 μm.

Test A-5 polymethyl methacrylate dispersion seed with didecanoyl peroxide

A solution of PVP K-30 (93.75 g) in methanol (2635 g) was added to the reactor and the mixture was for Cooked for 1 hour in an N2 atmosphere. The mixture was cooled to 55 ° C before methyl methacrylate (375 g) was added. A mixture of didecanoyl peroxide (18.77 g) and methanol (585 g) was preheated to 30 ° C and loaded into the reactor. The polymerizations were for 15 to Performed at 55 ° C for 24 hours.

The particles produced had one Diameter of 8 μm.

Test A-6 polymethyl methacrylate dispersion seed with didecanoyl peroxide

A solution of PVP K-30 (18.75 g) in methanol (644.25 g) was added to the reactor and the mixture was for Cooked for 1 hour in an N2 atmosphere. The mixture was cooled to 55 ° C before methyl methacrylate (75 g) was added. A mixture of didecanoyl peroxide (3.75 g) and methanol (116.87 g) was preheated to 30 ° C and loaded into the reactor. The polymerization was continued for 24 hours 55 ° C carried out.

The particles produced had one Diameter of 7 μm.

Test A-7 Activated polystyrene dispersion seed

A solution of PVP K-30 (5.15 g) in methanol (240.11 g) was added to the reactor and the mixture was for Heated for 1 hour in an N2 atmosphere. The mixture was cooled to 70 ° C before styrene (78.04 g) was added has been. A mixture of 2,2-azobis (isobutyronitrile) was added to the reactor (2.34 g) and ethanol (31.20 g) added when the temperature was stable was at 70 ° C. The polymerization was for 24 hours performed at 70 ° C.

The particles produced had one 6.0 µm diameter.

Some of these germ particles (5.0 g) in distilled water (25.40 g) was further mixed with an emulsion from dioctanoyl peroxide (0.5 g), sodium lauryl sulfate (0.083 g) and distilled water (16.67 g) swollen. The swelling took place for about 20 hours at 25 ° C, and the finished, activated germ had a diameter of 6.2 μm.

Production of PVC particles in of the order of magnitude from 10 to 50 μm with a seed-based polymerization.

Test B-1

Methylhydroxypropylcelullose dissolved in distilled Water (2 g / l, 66.25 g), sodium lauryl sulfate (0.05 g) and activated Oligomer seeds from Example A-1 (0.26 g) were at 25 ° C heated. N2 gas was added at a pressure of 9 bar. The reactor was then evacuated to remove oxygen. VCM (18.75 ml) was admitted and could for Swell into the germ particles for 60 minutes. It was a solution from Methyl hydroxypropyl cellulose in distilled water (2 g / l, 33.75 g) and potassium iodide (0.038 g) were added to the reactor before the temperature increased to 55 ° C has been. The polymerization started and continued until a pressure drop of 2.5 bar was registered in the reactor. The reaction was then stopped by cooling the reactor to 20 ° C, and unconverted monomer was released.

The particles produced had a concave surface, as in 1 is shown. The diameter was approximately 15 μm.

Test B-2

Methyl hydroxypropyl cellulose, dissolved in distilled Water (10 g / l, 100 g), sodium lauryl sulfate (0.05 g), potassium iodide (0.038 g) and oligomer seed from Example A-1 (0.52 g) were on Heated 30 ° C, the reactor was filled with N2 and the oxygen was removed as in B-1. VCM (15 ml), vinyl acetate (5 ml) and a solution of Azobismethylbutyronitrile (0.25 g) and methanol (0.25 g) were added added to the reactor and allowed to enter the seed particles for 60 minutes swell. Then the temperature was raised to 55 ° C and the same Procedure as in B-1 followed. The particles produced were spherical with about a diameter 7 μm.

Test B-3

Exactly the same procedure as in B-2 was followed, with the difference that the amount of VCM was from 15 ml increased to 18 ml and the amount of vinyl acetate was reduced from 5 ml to 2 ml has been. The solution from methyl hydroxypropyl cellulose had a concentration of 6 g / l. The particles produced had a concave surface and about a diameter 10 μm.

Test B-4

Seed particles from Example A-2 (0.25 g) sodium lauryl sulfate (0.05 g), potassium iodide (0.038 g) and methylhydroxypropyl cellulose in distilled water (5 g / l, 100 g) were loaded into the reactor. The same procedure as in B-1 was followed. VCM (18.8 ml) was admitted and could for Swell into the germinal particles for 60 minutes at 25 ° C. The polymerization was carried out at 60 ° C, until a pressure drop of 2.5 bar was reached. There were spherical particles with a diameter of 13 μm manufactured.

Test B-5

The procedure from B-4 was followed with the difference that the activated polystyrene seed from example A-4 (0.26 g) were used as seed particles. It became concave Particles with a diameter of approximately 16 microns.

Test B-6

Seed particles from Example A-3 (6.8 m, 1.0 g), sodium lauryl sulfate (0.05 g), potassium iodide (0.038 g) and methylhydroxypropylcelullose in distilled water (2 g / l, 100 g) were loaded into the reactor. After oxygen removal, VCM (17 ml) and a solution from azobismethylbutyronitrile (0.25 ml) and methanol (0.25 g) added, and could for Swell in the germ particles for 60 minutes. The polymerization was carried out at 60 ° C, until a pressure drop of 2.5 bar was reached. There were spherical particles with a diameter of approximately 11 μm.

Test B-7

The procedure of B-7 was followed with the difference that 34 ml VCM was added instead of 17 ml were. There were particles with a concave surface and a size of about 14 microns.

Test B-8

Seed particles from Example A-3 were with 2-ethylhexythioglycolate (0.15 g), (12.5 µm, 2.00 g), sodium lauryl sulfate (0.05 g), potassium iodide (0.038 g) and methylhydroxypropyl cellulose in distilled water (2 g / l, 100 g) added to the reactor and the oxygen was removed before VCM (20 ml) and a solution of 2,2-azobis (isobutyronitrile) (0.25 g) and methanol (0.25 g) were added. After swelling into the germ particles for The temperature was raised to 60 ° C. for 2 hours and the Polymerization was carried out until a pressure drop of 2.5 bar was reached. Spherical particles with a diameter of 20 μm and a small fraction of smaller particles were made.

Test B-9

Seed particles from Example A-3 (6.8 μm, 1.0 g), sodium lauryl sulfate (0.05 g), potassium iodide (0.038 g) and methylhydroxypropyl cellulose in distilled water (2 g / l, 100 g) were added to the CPA Reactor loaded. After removal of oxygen, VCM (7 ml) and a solution of azobismethylbutyronitrile (0.35 g) and Methanol (0.35 g) was added and allowed to swell in the seed particles for 60 minutes. The temperature was raised to 60 ° C and VCM (20 ml) was then continuously added to the reactor using a piston pump. The pressure in the reactor was thus kept constant, just below the saturation pressure at 60 ° C. The reaction continued until a total pressure drop of 2.5 bar was reached.

There were spherical particles with a diameter of about 18.5 μm manufactured. An examination under a scanning electron microscope (SEM) showed small particles on the surface of the spherical particles were absorbed. This was due to the formation of new particles the watery Phase as previously described.

Test B-10

Seed particles from example A-3 (6.8 μm, 2.2 g), Sodium lauryl sulfate (0.33 g), potassium iodide (0.25 g) and methyl hydroxypropyl cellulose in distilled water (2 g / l, 650 g) was added to the reactor. After evacuation, VCM (37.5 ml) and a solution were made Azobismethylbutyronitrile (1.0 g) and methanol (1.0 g) added and could for Swell in the germ particles for 60 minutes. The temperature was up 60 ° C increased and then VCM (94.5 ml) was added by continuous addition added by a piston pump. The addition was regulated so that the pressure was constant just below the saturation pressure. The polymerization was terminated as a pressure drop of 2.5 bar was reached.

There were spherical particles with a diameter of about 18 μm. Small adsorbed particles were again observed on the surface.

Test B-11

Seed particles from example A-3 (7.2 μm, 6.1 g), Sodium lauryl sulfate (0.28 g), potassium iodide (0.21 g) and methyl hydroxypropyl cellulose in distilled water (2 g / l, 550 g) was added to the reactor. After evacuation, VCM (20 ml) and a solution were made Azobismethylbutyronitrile (1.0 g) and methanol (1.0 g) added and could for Swell in the germ particles for 60 minutes. The temperature was up 60 degrees increased and VCM (160 ml) was added continuously as in B-9. The Polymerization was carried out until a pressure drop of 2.5 bar was reached.

Spherical particles of 18 μm were produced. Small adsorbed particles were observed on the surface as shown in 2 is shown.

Test B-12

Seed particles from example A-3 (1.0 μm, 10.3 g), Sodium lauryl sulfate (0.28 g), potassium iodide (0.21 g) and methyl hydroxypropyl cellulose in distilled water (2 g / l, 550 g) was added to the reactor. After evacuation, VCM (20 ml) and a solution were made Azobismethylbutyronitrile (1.0 g) and methanol (1.0 g) added and could for Swell in the germ particles for 60 minutes. The temperature was up 60 degrees increased and VCM (155 ml) was added continuously as in B-9. There were spherical Particles made of 3 microns.

Test B-13

Two 14 liter reactors were installed connected in series. Reactor 1 was loaded with methyl hydroxypropyl cellulose (13.00 g) dissolved in water (6056 g), potassium iodide (2.47 g) and PMMA dispersion seed (8 μm, 100 g), prepared as in Example A-3. The reactor 1 was at 30 ° C heated. Both reactors were evacuated to remove and oxygen the connection between them was closed by means of a valve. VCM (2890 ml) was added to reactor 2.

Azobismethylbutyronitrile (22.82 g), solved in methanol (22.82 g) along with VCM (300 ml) became the reactor 1 added. After 1 hour during which the VCM and the initiator in the seed particles swelled, the temperature was raised to 60 ° C elevated. The reactor 2 was heated to 57 ° C. With a stable Temperature in reactor 1, the valve was opened and the temperature in Reactor 2 is regulated against the pressure in reactor 1 so that it is constant was held until the VCM disappeared into the system as a separate phase. The temperature range for Reactor 2 was 57 to 65 degrees.

Spherical particles with a diameter of 25 μm were produced with a uniform surface, as in 3 is shown.

Test B-14

Two 14 liter reactors were connected in series. Reactor 1 was loaded with methylhydro xypropyl cellulose (13.00 g) dissolved in water (6056 g), potassium iodide (2.47 g), sodium lauryl sulfate (11.21 g) and PMMA dispersion seed (8 μm, 100 g), prepared as in Example A-3. The reactor 1 was heated to 30 ° C. Both reactors were evacuated to remove oxygen and the connection between them was closed by means of a valve. VCM (2890 ml) was added to reactor 2. Azobismethylbutyronitrile (22.82 g) dissolved in methanol (22.82 g) was added to Reactor 1 along with VCM (300 ml). After 1 hour in which the VCM and the initiator swelled into the seed particles, the temperature was raised to 60 ° C. The reactor 2 was heated to 57 ° C. At a stable temperature in reactor 1, the valve was opened and the temperature in reactor 2 was regulated against the pressure in reactor 1 so that it was kept constant until the VCM disappeared as a separate phase in the system. The temperature range for reactor 2 was 57 to 65 degrees.

There were spherical particles with a diameter of 15 μm manufactured with a non-uniform surface from precipitated Secondary particles.

Test B-15

Seed particles from example A-6 (7.0 μm, 7.50 g), which initiator, sodium lauryl sulfate (0.25 g), potassium iodide (0.19 g), methyl hydroxypropyl cellulose in distilled water (2 g /, 1.00 g), copper sulfate pentahydrate (2.00 mg) and water (630.40 g) contained were added to the reactor. After an evacuation VCM (20 ml) was added and allowed to enter the seed particles for 60 minutes swell. The temperature was raised to 60 ° C and VCM (130 ml) was continuously added with a piston pump. Around Controlling the reaction rate became a solution ascorbic acid (4 g / l, 2.00 ml) added. The reaction was continued until a pressure drop of 2.5 bar was reached.

13 μm spherical particles were produced.

Test B-16

Activated polystyrene seed particles from example A-7 (6.2 μm, 1.00 g), potassium iodide (0.038 g) and methylhydroxypropyl cellulose in distilled water (2 g / l, 100 g) was added to the reactor. After removal of oxygen, VCM (7 ml) was added and could for Swell in the germ particles for 60 minutes. The temperature was up 60 ° C increased and VCM (22.5 ml) was then added continuously to the reactor added to a piston pump. The reaction was continued until a pressure drop of 2.5 bar was reached.

There were particles with a diameter of about 15 μm. The particles had a non-uniform surface and were not spherical.

For comparison shows 4 a commercial filler PVC, Vinnol C65V, from Vinnolit GmbH.

The use of the using PVC particles produced in the present invention is used in the following examples:

Test C-1

PVC pastes were manufactured according to the in Formulations given in Table 2. PVC powder was made with plasticizer and a liquid Thermal stabilizer mixed in a fast warring mixer. The Mixing took place for 10 minutes with an elevated Speed at a final temperature of 35 ° C. The viscosity the paste was in a Bohlin VOR rheometer, C14 measuring system measured with increasing shear rates from 1 to 300 per Second. The particle size of the dispersed PVC particles were measured by spreading a thin film the pastes on a grindometer (stick). The particle size will be indicated here at the time the streak in the thin film occur. The films were in a Wemer-Mathis oven for 3 minutes plasticized at 200 ° C. The films were then in view checked for any foaming. The water absorption in the films were measured as weight gain after storage in water at 50 ° C for 48 hours.

Pevikon P14

Standardpasten-PVC, Norsk Hydro a. s

Pevikon DP1502

Entwicklungsprodukt, fein-gekörntes Pasten-PVC, Norsk Hydro a. s

Vinnol C65V

Extender-PVC (Füllstoff-PVC), Vinnolit GmbH

DOP

Diethylhexylphthalat

LZ616

Bariumzinkstabilisator, Ackros

ESO

epoxidiertes Sojabohnenöl

MM-11

in Beispiel B-11 hergestellte Partikel

MM-13

in Beispiel B-13 hergestellte Partikel

MM-14

in Beispiel B-14 hergestellte Partikel

MM-15

in Beispiel B-15 hergestellte Partikel

Table 2

Pevikon P14

Standard paste PVC, Norsk Hydro a. s

Pevikon DP1502

Development product, fine-grained paste PVC, Norsk Hydro a. s

Vinnol C65V

Extender PVC (filler PVC), Vinnolit GmbH

DOP

diethylhexylphthalate

LZ616

Barium zinc stabilizer, Ackros

ESO

epoxidized soy

MM-11

Particles made in Example B-11

MM-13

Particles made in Example B-13

MM-14

Particles made in Example B-14

MM-15

Particles made in Example B-15

Table 3 shows the viscosities and Particle sizes for the nine Formulations. It can be clearly seen that the samples with PVC particles according to the present Invention to provide film coating properties which thinner than 50 μm are. Even if more than 70 phr of PVC filler PVC content is very thin Films made. Pastes with low viscosity are produced at the same time. The meaning of perfectly spherical Particles with a uniform surface can be seen clearly in a comparison of viscosities of Formulations 1, 2, 3 and 4. Sample MM-14 has irregularities in the form of the precipitated Particles on the surface. The viscosity was very high. It can also be seen that in this case not possible was, the particles completely down to their primary particle level to disperse and the smear on the grindometer showed one Particle size of 75 μm.

Table 3

In combination with a very fine grained Standard paste PVC (Pevikon DP1510), result in filler PVC particles according to the present Invention the unique opportunity to produce films down to 50 μm, and at the same time the viscosity the paste is low and the rheology is level Newtonian shows, although only 44 phr liquid substance used in the formulation (F-7, 8 and 9). Until now this with known PVC types for Plastisol purposes not possible been.

Claims (13)

Process for the production of PVC particles with a narrow size distribution in the order of 10 to 50 microns and preferably 10 to 30 microns, characterized in that in a first stage an aromatic vinyl monomer, acrylates or a mixture of monomers is polymerized to a polymer / Oligomer seed particles in the order of 1 to 10 microns to form, after which a vinyl chloride monomer or a mixture of monomers is swollen in the polymer / oligomer seed particles and the polymerization is carried out in such a way that they become polymer particles of the desired size grow. A method according to claim 1, characterized in that the seed particles manufactured in the first stage in a two-stage swelling process become. A method according to claim 1, characterized in that the seed particles produced in the first stage by dispersion polymerization become. A method according to claim 3, characterized in that the dispersion polymerization by a preheated mixture of an initiator and a solvent is initiated, which is added to the reaction mixture, so that the Temperature in the medium during the period in which the particles are germinated is not significant changed. A method according to claim 1, characterized in that the particles are separated from the reaction medium and washed by additives before transferring to the second stage of the process the. A method according to claim 3, characterized in that the by Dispersion polymerization produced seed particles before the polymerization in the second stage by swelling in a mixture of an oil-soluble Initiator and monomers are activated before the initiator decomposes, and for the execution of the Polymerization more monomer is added. A method according to claim 1, characterized in that in the first stage an oil-soluble organic peroxide or an azo initiator as a polymerization initiator is used. A method according to claim 1, characterized in that the polymerization in the second stage using the remaining initiator executed in the seed particles becomes. A method according to claim 1, characterized in that the second Stage with continuous monomer addition is carried out to phase separation problems to avoid. A method according to claim 1 for the production of spherical PVC particles on the order of 10 to 50 μm, characterized in that the Seed particles in a first stage by dispersion polymerization an aromatic vinyl monomer, acrylates or a mixture be produced from monomers in which an oil-soluble organic peroxide is used as a polymerization initiator, and that in a second stage only the polymerization medium, stabilizing agent, Vinyl chloride monomer or a mixture of monomers and if possible are added in connection with so-called redox systems, and that the Second stage polymerization using the leftover Initiator is carried out in the seed particles. Use of particles which have been produced according to claims 1 to 10, as a viscosity reducing agent in other polymer systems or in liquids where other polymer systems are not available as filters in columns for separation purposes or as Base particles for another chemical change. PVC mixture, especially for Plastisol purposes, characterized in that the mixture spherical PVC particles in the order of magnitude from 10 to 50 μm and in particular 10 to 30 μm with a narrow size distribution according to claims 1 to 10, normal paste PVC 0 to 100 parts plasticizer, 0.1 to 10 parts of heat stabilizer and 0 to 100 parts of others normal additive for contains products based on PVC. spherical Particles in the order of magnitude from 10 to 50 μm and in particular 10 to 30 μm with a narrow size distribution, characterized in that the Particles produced in a two-stage polymerization process become. wherein the germ particles that pass through in a first stage Dispersion polymerization of an aromatic vinyl monomer, from Acrylates or a mixture of monomers in which an oil-soluble organic Peroxide is used as a polymerization initiator have been transferred to a second stage in which only the polymerization medium, stabilizing agent, vinyl chloride monomer or a mixture of monomers and if possible in combination with so-called Redox systems are added, and that the polymerization in the second stage using the remaining initiator executed in the seed particles becomes.